The present invention relates to an airbag for a vehicle.
Airbags that are intended to protect the heads of the vehicle occupants in a lateral impact are designated as head side airbags or curtain airbags, and are arranged in the region of the vehicle roof. If an airbag of this kind deploys, the chamber or chambers of the airbag is/are filled with gas, as a result of which the airbag emerges from the vehicle roof to protect the vehicle occupants in the lateral regions of the vehicle. In this context, an airbag of this kind is constructed such that the gas-filled chambers lie as closely as possible next to the side structure of the vehicle, that is to say for example in the region of the side window. In addition, it is also necessary, when the airbag is in the inflated condition, for the chamber or chambers to be located at those points in the vehicle interior at which protection is intended to be provided. Consequently, on the one hand the intention is to prevent the entire airbag from moving into the interior, away from the side structure of the vehicle, to prevent body parts of persons in the vehicle from coming between the airbag and the corresponding side structure of the vehicle. On the other hand, the gas-filled chambers of the airbag must be arranged where protection is required, as far as their vertical position is concerned. As a result, the chambers of the airbag must not be arranged too low in the vehicle nor arranged too high up.
It is known to secure so-called side airbags in the region of the vehicle roof, in particular in the region between the vehicle roof and the lateral region of the vehicle, by securing tabs arranged on the airbag. Typically, in this context, a plurality of tabs lying one behind the other as seen in the direction of the vehicle are used, and may be constructed for example with holes which ultimately serve to arrange the airbag on the vehicle body.
It has now been found that inflating the chamber or chambers of the airbag gives the airbag a tendency to move in the direction of the vehicle roof, that is to say to adopt a position which is undesirable, and hence leaves a region of the vehicle side structure unprotected at the downwardly directed free end. There is furthermore a tendency for the airbag to swing into the vehicle interior.
There is provided in accordance with one aspect of the present invention an airbag which is constructed such that on the one hand moving away from the region to be protected is prevented and on the other hand a desired vertical position of the airbag can be achieved with optimum material savings.
The fundamental idea of the inventive construction of the airbag resides in constructing the securing portions which are used to secure the airbag in the region of the vehicle roof or roof arch, and which may also be called tabs, such that these have inflatable regions. The inflatable regions in the securing portions or tabs on the one hand ensure additional stability of the airbag in the vertical direction, so that the airbag or the chamber of the airbag is prevented from drifting upwards on inflation, which was hitherto the case, since the tabs used have no stability of themselves. In other words, the airbag or the upwardly directed end regions of the chambers of the airbag are prevented from extending too far upwards and hence exposing a lower, unprotected region. On the other hand, the inflatable regions in the securing portions also produce stability in the horizontal direction, as a result of which the tendency of the airbag to move into the vehicle interior, in other words to perform a rotary movement about the securing means, is greatly reduced. Moreover, and advantageously, a minimum required volume of the chamber or chambers of the airbag can be maintained. It is accordingly not necessary to construct the chambers to be more voluminous in order to obtain the effect that the lower marginal regions of the chambers extend further down in the inflated condition. This results in a not inconsiderable saving on material. While maintaining the hitherto conventional volume of the chamber or chambers of an airbag module arranged laterally on the vehicle, it is consequently possible to achieve the desired vertical position, and at the same time it is possible to prevent the airbag having a tendency to move towards the interior.
It can be seen that maintaining a side airbag in the desired location cannot be achieved simply by constructing the securing means or tabs to be longer, since the airbag, in dependence on the opening pulse, that is to say when the chambers inflate, on the one hand has a tendency to roll over, that is to say to swing upwards and hence away from the side region of the vehicle. Moreover, simply lengthening the securing means would not be able to prevent the further tendency of the airbag to push itself back under the roof lining on inflation and hence to upwardly displace its horizontal position in an undesirable manner. By constructing the securing means with inflatable regions, pillar-like regions are created which prevent the tendencies mentioned above.
In an advantageous embodiment, the securing portions having the inflatable regions are formed from the material of the airbag and are connected in one piece thereto. It is thus possible to attain the desired shaping of the airbag already at the time of manufacturing the airbag, with minimal additional use of material. Moreover, the fact that the securing portions are in one piece with the material of the airbag ensures that they cannot become detached from the rest of the airbag, with the result that the airbag does not tear away from the securing means as a result of the opening pulse.
Expediently, the inflatable regions of the securing means project, as seen from the chamber, into the securing portions and moreover have a marginal region adjoining the latter and facing the free ends of the securing portions. The marginal region which is arranged at the free ends of the securing portions, and is also capable of being provided in the lateral region of the securing portions as well, ensures among other things that the inflatable regions are sufficiently protected from undesirable tearing open.
Advantageously, devices for arranging the airbag on the vehicle body are constructed in the marginal region of the securing means, expediently in the region of the free ends of the securing means. These may for example be openings through which the corresponding securing means reach to securely arrange the airbag on the vehicle body.